M82 Barrett light fifty H&K21 German 7.62mm General Purpose Machine Gun!
Barrett Firearms Manufacturing was founded by Ronnie Barrett for the sole purpose of building semi-automatic rifles chambered for the powerful 12.7×99mm NATO (.50 BMG) ammunition, originally developed for and used in M2 Browning machine guns. Barrett began his work in the early 1980s and the first working rifles were available in 1982, hence the designation M82. Barrett designed every single part of the weapon personally and then went on to market the weapon and mass produce it out of his own pocket. He continued to develop his rifle through the 1980s, and developed the improved M82A1 rifle by 1986.
The HK21 has a heavy, quick-change barrel fitted with a slotted flash suppressor and adjustable iron sights with a hooded foresight and an aperture rear sight adjustable from 100 through 1200 m in 100 m increments. By simply swapping out several components such as the barrel, bolt and feed unit, the weapon can be quickly converted to the intermediate 7.62x39mm and 5.56x45mm calibers.